1. Field of the Invention
The present invention relates generally to tailgate constructions for pick-up trucks and other vehicles which permit the passage of air therethrough to reduce drag on the vehicle associated with the tailgate construction when the vehicle is in use.
2. Description of the Prior Art
Many types of vehicles have an open top cargo compartment which is closed at the rear end by a tailgate which can be raised and lowered to permit access to the cargo compartment. For example, most pick-up trucks and various trailers typically have such open tops.
It often happens that these type vehicles are driven for long distances with the cargo compartment either empty or very lightly loaded. For example, this is the case where pick-up trucks have as their primary use passenger transportation. The traditional pick-up truck has a rear end of the open top cargo compartment which is closed by a solid tailgate which forms an integral part of the cargo bed structure and thus is typically closed when the vehicle is in operation. When the vehicle is driven with the solid tailgate in the closed position, it causes the tailgate to interrupt or obstruct the flow of air which increases the drag on the vehicle and reduces gas mileage. A significant loss in fuel economy occurs because of the power which is wasted in overcoming this air drag resistance.
Despite the fact that several hinged or louvered tailgate constructions are known in the prior art, certain disadvantages have never been overcome. For example, many of the prior art designs were complicated in nature and utilized a number of mechanical moving parts such as hinges, cranks, and the like. One example is shown in U.S. Pat. No. 4,867,499, issued Sep. 19, 1989, to Stephan et al.
Other of the prior designs were simpler in nature, often consisting of a mere wire grate which served as a replacement for the traditional tailgate. U.S. Pat. No. 4,201,411, issued May 6, 1980, to Morgan, is one variation of this concept. While these designs reduce the effect of air resistance and drag on the vehicle, they are often not esthetically pleasing and require that an entire custom tailgate assembly be provided to replace the stock tailgate.
It is an object of the present invention to provide an improved low drag tailgate which overcomes these and other disadvantages of the prior art.
Another object of the invention is to provide such a low drag tailgate which is simple in design and economical to manufacture.
Another object of the invention is to provide such a low drag tailgate which can be provided as an assembly to be installed within openings provided in a stock vehicle tailgate, allowing the original tailgate to be retained within the end opening of the cargo bed compartment.
Another object of the invention is to provide such a low drag tailgate with a special counterweight mechanism which provides an improved operation of the pivotally mounted louvers of the assembly.